Issue with cylindrical surface source

Source Definition
1

Hello,

I’m attempting to model a proton flux through a beryllium cylinder. The Be cylinder is surrounded by a vacuum region, and then surrounded by a black hole region. I’ve tried to define the proton source as a cylindrical surface source surrounding the Be cylinder in the vacuum region. I’ve done this using the CYLI-VOL option in BEAMPOS. The source is also isotropic with an energy spectrum which I’ve defined using the source_newgen.f user routine. The simulation is running without any errors, but the simulation is stuck on 0% for a significantly long period of time, so I’m not sure what the issue is.

be_cyl_gcr.flair (3.2 KB)
be_cyl_gcr.inp (2.3 KB)
gcr_source.txt (1.3 MB)
gcrsource_newgen_v2.f (19.1 KB)

Thanks,

Emma

2

Dear Emma,

if you are using a source_newgen routine, the BEAMPOS card with the CYLI-VOL card is ignored. You need to implement the spatial sampling by yourself using the coordinate_x/y/z variables.

Cheers,
David

3

Thanks, David. I set the coordinates in the source_newgen.f file:

  coordinate_x = 0.0D0
  coordinate_y = 0.0D0
  coordinate_z = 64.82D0

and set an annular distribution

call sample_annular_distribution( 49.2633D0, 50.0D0, coordinate_x, coordinate_y )

which from my understanding will sample from an infinite annular cylinder in the z-direction centered at (0.0,0.0).
However when I try to run the simulation is still getting stuck on 0%.

be_cyl_gcr.flair (3.2 KB)
gcrsource_newgen_v2.f (19.1 KB)

Thanks

5

Dear Emma,

sorry for the late reply! The problem with your input is with the LAM-BIAS card. You should make sure that you are not over biasing, otherwise the required time for following even one primary gets extremely long.

Cheers,
David

6

Oh yes that makes sense, thank you!